1. Field of the invention
The present invention relates to a side airbag for a vehicle, and more particularly, to a side airbag for a vehicle installed at a side of a driver or a passenger to protect the driver or passenger when a side collision of a vehicle occurs, together with an airbag installed in front of a driver seat or a passenger seat.
2. Description of the Prior Art
As is well known, an airbag is installed in a vehicle to lessen impact applied to a driver or a passenger when a vehicle collision occurs, together with a safety belt, thereby protecting the driver or passenger.
In particular, the airbag is installed in front of a driver seat or a passenger seat to protect a driver or a passenger. When a vehicle collides with another object or abruptly stops, the airbag is inflated to prevent the driver or passenger from being inclined and directly collided with, for example, a steering wheel or an instrument panel, thereby absorbing impact applied to the driver or passenger.
The airbag is operated by a collision detection sensor and an electronic control unit (ECU) when a vehicle collision occurs. When the collision occurs, the collision detection sensor detects the collision to transmit a collision signal to the ECU, and the ECU determines operation of the airbag depending on the magnitude of the collision to operate an inflator, thereby deploying the airbag.
At this time, the inflator receives an operation signal form the ECU to operate a heater to ignite gunpowder. As a result, a gas generating agent is combusted to instantly generate a large amount of expansion gas to inject the expansion gas into the airbag, thereby expanding the airbag.
Meanwhile, in recent times, in order to protect a driver or a passenger even when a side collision of a vehicle occurs, a side airbag has been installed inside a door to protect the driver or passenger.
The side airbag is installed at a roof rail over a front seat or a rear seat to protect the driver or passenger by operating the inflator and deploying the side airbag when the side collision of a vehicle occurs.
Various side airbags have been developed, and a typical structure is shown in FIG. 1.
As shown in FIG. 1, a side airbag for a vehicle includes a chest bag 102 and a head bag 101. The chest bag 102 includes a mounting part 104 having a neck shape formed at its rear side, and a lower part 106 integrally formed with the mounting part 104.
In addition, the side airbag has a substantially symmetrical shape with respect to a tether 103. The tether 103 is disposed between the chest bag 102 and the head bag 101. A vent hole is formed far away from the mounting part 104, the head bag 101 extends from the chest bag 102 in a substantially symmetrical manner, and a pulling plate 105 is disposed between the chest bag 102 and the head bag 101.
The side airbag has an advantage of reducing vibration when the airbag is deployed. However, since the side airbag is separately installed at a front seat or a rear seat, much time for installation of the side airbag is consumed and a large number of processes are required, thereby decreasing working performance.
In order to solve the problem, a side airbag shown in FIG. 2 has been proposed.
As shown in FIG. 2, a side airbag for a vehicle includes an airbag 200 installed in a headlining of a roof side panel 100, and an inflator 300 installed at one side of the airbag 200 and accommodating a gas generating agent therein to deploy the airbag when a side collision occurs.
The side airbag has a guide member 220 having one end connected to the airbag 200 and the other end pivotally installed at the roof side panel 100.
The above side airbag has an advantage of covering a front seat and a rear seat using a single airbag. However, since the airbag cushion is deployed in a direction perpendicular to a flow direction of a gas generated from an inflator, it is difficult to rapidly protect a driver or a passenger.
In addition, the side airbag deforms a front pillar panel assembly of a roof rail, in particular, a portion between a front wind glass and a front door glass to deteriorate an appearance of the vehicle. That is, the gas inflates from the inflator with a high pressure to instantly deploy the airbag to apply impact to the roof rail, thereby deforming the roof rail.
Further, since it is difficult to gradually adjust an expansion pressure of the side airbag depending on deployment circumstance of the side airbag, the side airbag may apply a strong impact to a driver or a passenger to possibly make the driver or passenger collide with another part of the vehicle, thereby causing damage due to the airbag.